How do you "try" many versions? Do you or do you not have a Mac?
I use Mac OS X at home and Windows Vista at work. I really prefer Mac OS X, although (or perhaps because) I spend more time in Vista.
Pet peeves:
Windows Vista programs steal the focus. When I launch a program and it takes a while to load, and I switch to another program, in Windows Vista the launched program will at some point steal focus and interrupt my typing. In Mac OS X, the launched program will simply appear behind the current window.
I cannot easily select specific text in Windows Vista. For some reason Windows always decides that I must select more or less than I am trying to select. (Try selecting the phrase "another pr" in the paragraph above and you will see what I mean.) Also, double-clicking a word in Mac OS X will select the word and nothing but the word. That is very clean. In Windows, it will select the word and the space behind it, unless there is no space behind the word. Hence what I will have in the clipboard might or might not have a space and I have to check when I paste it somewhere. This is particularly annoying when copying and pasting passwords, because you cannot see them when you paste them.
The system settings in Mac OS X are all in one place and I can easily tell where they are (Apple menu, System Preferences). They also have simple names. In Windows Vista, everything takes a few clicks more and I cannot remember which settings applet is for what and why some are in the control panel while others are in the "Personalize" sub-folder in the control panel. (The disctinction does not appear to be system-wide vs. per-user, as PDA syncing is in the control panel with parental controls and "Add Hardware" while "Personalize" contains only per-user settings.)
The command line window in Windows does not allow for easy copying and pasting of text and if you do copy and paste, it does not recognize a command line as a line of text to be copied:
C:\Documents and Settings\Andrew Brehm>very long command line that I ty
ped to show what is going on
'very' is not recognized as an internal or external command,
operable program or batch file.
C:\Documents and Settings\Andrew Brehm>
(This is from XP but Vista behaves exactly like it.)
Mac OS X recognizes "very long command line that I typed to show what is going on" as a line of text and copies it as such.
Everything is implemented cleaner in Mac OS X. It is a lot easier to describe where to change a certain setting. Windows Vista is just more difficult to use.
And this is just the things that could easily be changed. Windows has a few deep usability problems that cannot be fixed easily any more. For example Mac OS X uses a key combination for "copy" (Apple-c) that is not the same as the key combination for "break" in a terminal (ctrl-c). Hence copying and pasting in Mac OS X's command line works just as in any other program. Try copying and pasting between a GUI program and an editor running in command line window!
Mac OS X's terminal understands all common control codes (ctrl-c for break or cancel, ctrl-d for end of transmission/file, ctrl-z for suspend, ctrl-a for navigating to beginning of line, ctrl-e for navigating to end of line, ctrl-k for removing text, ctrl-y for putting it back), most of which are also understood by all Cocoa (but not Carbon) programs. Windows has no such consistency. In Mac OS X I can copy and paste between Emacs and a native Cocoa program using the same keyboard shortcuts, in Windows I cannot, unless I use a nativ Win32 GUI port of Emacs.
Mac OS X also doesn't keep displaying idiotic messages that I don't want to read again and again and keep dismissing. It's just cleaner and less annoying.
Mac OS X simply doesn't do a lot. It stays away from me. It doesn't do much that annoys me. Whenever there is something where a solution that I don't like would annoy me, OS X simply doesn't have a solution. Like I might _want_ the OS to try to predict what I am trying to select. But Windows does it wrong. That's annoying. OS X doesn't try to predict. That is better. It cannot possibly annoy me.
I have just tried out RISC OS (native OS for ARM CPUs) and it is even cleaner than Mac OS X, or so it seems. Very non-annoying, better than OS X. But both don't compare to Windows when it comes to annoying features.
Clicks to change screen resolution:
Mac OS X: 4
RISC OS: 3
Windows Vista: 5
Every click adds complexity because it changes the state of the interface and makes the interface offer new choices to consider.
(OS/2 is worse than Windows Vista. I never know where to find any setting in eComStation and sometimes I find the setting doesn't even exist. Most Linux distributions are even worse. And the more Linux distributions there are, the worse it gets.)